Valdecoxib of formula (1):
or 4-(5-Methyl-3-phenyl-4-isoxazolyl)benzenesulfonamide is a highly selective and potent cyclooxygenase-2 inhibitor in human whole blood and useful for the treatment of arthritis and pain. The therapeutic uses of valdecoxib are disclosed in WO 9625405.
Two novel forms of valdecoxib, form A and form B, are mentioned in WO 9806708.
We have discovered three stable novel crystalline forms of valdecoxib and these forms are found to be suitable for pharmaceutical preparations.
The object of the present invention is to provide stable novel crystalline forms of valdecoxib, processes for preparing these forms and pharmaceutical compositions containing them.